But as our more eminent, and peculiarly human, faculties are of various
orders, moral, intellectual, and aesthetic, the question presents
itself, is there any one of these whose development is the predominant
agency in the evolution of our species? According to M. Comte, the main
agent in the progress of mankind is their intellectual development.

Not because the intellectual is the most powerful part of our nature,
for, limited to its inherent strength, it is one of the weakest: but
because it is the guiding part, and acts not with its own strength
alone, but with the united force of all parts of our nature which it can
draw after it. In a social state the feelings and propensities cannot
act with their full power, in a determinate direction, unless the
speculative intellect places itself at their head. The passions are,
in the individual man, a more energetic power than a mere intellectual
conviction; but the passions tend to divide, not to unite, mankind: it
is only by a common belief that passions are brought to work together,
and become a collective force instead of forces neutralizing one
another. Our intelligence is first awakened by the stimulus of our
animal wants and of our stronger and coarser desires; and these for
a long time almost exclusively determine the direction in which our
intelligence shall work: but once roused to activity, it assumes more
and more the management of the operations of which stronger impulses are
the prompters, and constrains them to follow its lead, not by its own
strength, but because in the play of antagonistic forces, the path it
points out is (in scientific phraseology) the direction of least
resistance. Personal interests and feelings, in the social state, can
only obtain the maximum of satisfaction by means of co-operation, and
the necessary condition of co-operation is a common belief. All human
society, consequently, is grounded on a system of fundamental opinions,